Vapor ablation systems and methods

ABSTRACT

A vapor delivery system and method is provided that is adapted for treating prostate tissue. The vapor delivery system includes a vapor delivery needle configured to deliver condensable vapor energy to tissue. In one method, the vapor delivery system is advanced transurethrally into the patient to access the prostate tissue. The vapor delivery system includes a generator unit and an inductive heating system to produce a high quality vapor for delivery to tissue. Methods of use are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Pat. ApplicationNo. 62/109,540, filed Jan. 29, 2015, titled “VAPOR ABLATION SYSTEMS ANDMETHODS”, which is incorporated by reference in its entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

FIELD

The present invention relates to devices and related methods fortreatment of benign prostatic hyperplasia using a minimally invasiveapproach. More specifically, the present disclosure relates to treatingbenign prostatic hyperplasia with vapor delivered to the prostate.

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common disorder in middle-agedand older men, with prevalence increasing with age. At age 50, more thanone-half of men have symptomatic BPH, and by age 70, nearly 90% of menhave microscopic evidence of an enlarged prostate. The severity ofsymptoms also increase with age with 27% of patients in the 60-70 agebracket having moderate-to-severe symptoms, and 37% of patients in their70’s suffering from moderate-to-severe symptoms.

The prostate early in life is the size and shape of a walnut and priorto the enlargement resulting from BPH, weighs about 20 grams. Prostateenlargement appears to be a normal process. With age, the prostategradually increases in size to twice or more its normal size. Thefibromuscular tissue of the outer prostatic capsule restricts expansionafter the gland reaches a certain size. Because of such restriction onexpansion, the intracapsular tissue will compress against and constrictthe prostatic urethra, thus causing resistance to urine flow.

In the male urogenital anatomy, the prostate gland is located below thebladder and the bladder neck. The walls of the bladder can expand andcontract to cause urine flow through the urethra, which extends from thebladder, through the prostate and penis. The portion of urethra that issurrounded by the prostate gland is referred to as the prostaticurethra. The prostate also surrounds the ejaculatory ducts which have anopen termination in the prostatic urethra. During sexual arousal, spermis transported from the testes by the ductus deferens to the prostatewhich provides fluids that combine with sperm to form semen duringejaculation. On each side of the prostate, the ductus deferens andseminal vesicles join to form a single tube called an ejaculatory duct.Thus, each ejaculatory duct carries the seminal vesicle secretions andsperm into the prostatic urethra.

The prostate glandular structure can be classified into three zones: theperipheral zone, transition zone, and central zone. Peripheral zone PZcomprises about 70% of the volume of a young man’s prostate. Thissub-capsular portion of the posterior aspect of the prostate glandsurrounds the distal urethra and 70 to 80% of cancers originate in theperipheral zone tissue. The central zone CZ surrounds the ejaculatoryducts and contains about 20-25% of the prostate volume. The central zoneis often the site of inflammatory processes. The transition zone TZ isthe site in which benign prostatic hyperplasia develops, and containsabout 5-10% of the volume of glandular elements in a normal prostate,but can constitute up to 80% of such volume in cases of BPH. Thetransition zone consists of two lateral prostate lobes and theperiurethral gland region. There are natural barriers around thetransition zone, i.e., the prostatic urethra, the anterior fibromuscularstroma, and a fibrous plane between the transition zone and peripheralzone. The anterior fibromuscular stroma or fibromuscular zone ispredominantly fibromuscular tissue.

BPH is typically diagnosed when the patient seeks medical treatmentcomplaining of bothersome urinary difficulties. The predominant symptomsof BPH are an increase in frequency and urgency of urination, and asignificant decrease in the rate of flow during urination. BPH can alsocause urinary retention in the bladder which in turn can lead to lowerurinary tract infection (LUTI). In many cases, the LUTI then can ascendinto the kidneys and cause chronic pyelonephritis, and can eventuallylead to renal insufficiency. BPH also may lead to sexual dysfunctionrelated to sleep disturbance or psychological anxiety caused by severeurinary difficulties. Thus, BPH can significantly alter the quality oflife with aging of the male population.

BPH is the result of an imbalance between the continuous production andnatural death (apoptosis) of the glandular cells of the prostate. Theoverproduction of such cells leads to increased prostate size, mostsignificantly in the transition zone which traverses the prostaticurethra.

In early stage cases of BPH, pharmacological treatments can alleviatesome of the symptoms. For example, alpha-blockers treat BPH by relaxingsmooth muscle tissue found in the prostate and the bladder neck, whichmay allow urine to flow out of the bladder more easily. Such drugs canprove effective until the glandular elements cause overwhelming cellgrowth in the prostate.

More advanced stages of BPH, however, can only be treated by surgical orless-invasive thermal ablation device interventions. A number of methodshave been developed using electrosurgical or mechanical extraction oftissue, and thermal ablation or cryoablation of intracapsular prostatictissue. In many cases, such interventions provide only transient relief,and these treatments often cause significant peri-operative discomfortand morbidity.

In one thermal ablation method, RF energy is delivered to prostatetissue via an elongated RF needle being penetrated into a plurality oflocations in a prostate lobe. The elongated RF needle is typically about20 mm in length, together with an insulator that penetrates into thelobe. The resulting RF treatment thus ablates tissue away from theprostatic urethra and does not target tissue close to, and parallel to,the prostatic urethra. The application of RF energy typically extendsfor 1 to 3 minutes or longer which allows thermal diffusion of the RFenergy to ablate tissue out to the capsule periphery. Such RF energydelivery methods may not create a durable effect, since smooth muscletissue and alpha adrenergic receptors are not uniformly ablated aroundthe prostatic urethra or within the transition zone. As a result, tissuein the prostate lobes can continue to grow and impinge on the urethrathus limiting long-term effectiveness of the treatment.

SUMMARY OF THE DISCLOSURE

A vapor delivery system is provided, comprising a generator unitincluding a cradle, a syringe assembly disposed in the cradle andconfigured to interact with the cradle to deliver a fluid at acontrolled rate, an inductive heating system fluidly coupled to thesyringe assembly and configured to receive fluid from the syringeassembly, a force sensor disposed in the cradle and configured contactthe cradle and/or syringe assembly to generate an electrical signalproportional to a force exerted on the force sensor by the cradle and/orsyringe assembly, and an electronic controller configured controldelivery of fluid and RF power to the inductive heating system for theproduction of vapor, the electronic controller being further configuredto calibrate the electrical signal as representing a fluid pressurewithin the syringe assembly, the electronic controller being furtherconfigured to stop delivery of fluid and/or RF power to the inductiveheating system when the fluid pressure falls outside of a desired rangeof fluid pressures.

In some embodiments, the cradle is arranged such that a distal end ofthe syringe assembly is held at a higher elevation than a proximal endof the syringe assembly when the syringe assembly is inserted into thecradle.

In one embodiment, the cradle is configured to purge any air from thesyringe assembly during a priming procedure in which fluid is force fromthe syringe assembly through the vapor delivery system.

In another embodiment, the cradle further comprises a piston coupled toa linear motor, wherein the piston interacts with a plunger of thesyringe assembly to delivery fluid from the syringe assembly.

In some embodiments, a contact switch is activated when the syringeassembly is inserted into the cradle.

In one embodiment, the inductive heating system comprises an inner fluidcoil surrounded by an outer conductive coil.

A method of controlling a flow of vapor is provided, comprisingreceiving a syringe assembly into a cradle of a generator unit,delivering a fluid at a controlled rate from the syringe assembly to aninductive heating system fluidly coupled to the syringe assembly,measuring a force exerted on a force sensor that is disposed in thecradle and configured contact the cradle and/or syringe assembly duringfluid delivery, and calibrating the measured force with an electroniccontroller to represent a fluid pressure within the syringe assembly,and stopping delivery of fluid to the inductive heating system when thefluid pressure falls outside of a desired range of fluid pressures.

A method of treating prostate tissue is provided, comprising inserting avapor delivery system transurethrally into a patient to access theprostatic urethra of the patient, advancing a vapor delivery needlegenerally transverse to the vapor delivery system through the prostaticurethra and into a transition zone of the prostate, and delivering vaporthrough distally facing vapor delivery ports of the vapor deliveryneedle to direct the vapor distally from the device into the prostate.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the invention and to see how it may becarried out in practice, some preferred embodiments are next described,by way of non-limiting examples only, with reference to the accompanyingdrawings, in which like reference characters denote correspondingfeatures consistently throughout similar embodiments in the attacheddrawings.

FIG. 1 shows one embodiment of a vapor delivery system.

FIGS. 2A-2B show close-up views of a distal portion of the vapordelivery system including a vapor delivery needle.

FIGS. 2C-2D show a normal prostate and an enlarged prostate beingtreated with a vapor delivery system.

FIGS. 3A-3B show a vapor delivery system including an inductive heatingsystem for producing high quality condensable vapor.

FIG. 4 shows a generator unit configured to control generation of vaporin the inductive heating system.

FIG. 5 shows one embodiment of a syringe assembly that interacts withthe generator unit.

FIG. 6 shows a cross-sectional view of a syringe cradle and syringeassembly of the generator unit.

FIG. 7 is a cross-sectional view of a shaft of the vapor deliverysystem.

DETAILED DESCRIPTION OF THE INVENTION

In general, one method for treating BPH comprises introducing a heatedvapor interstitially into the interior of a prostate, wherein the vaporcontrollably ablates prostate tissue. This method can utilize vapor forapplied thermal energy of between 50 calories and 300 calories per eachindividual vapor treatment (and assumes multiple treatments for eachprostate lobe) in an office-based procedure. The method can causelocalized ablation of prostate tissue, and more particularly the appliedthermal energy from vapor can be localized to ablate tissue adjacent theurethra without damaging prostate tissue that is not adjacent theurethra.

The present disclosure is directed to the treatment of BPH, and moreparticularly for ablating transitional zone prostate tissue withoutablating central or peripheral zone prostate tissue. In one embodiment,the present disclosure is directed to treating a prostate usingconvective heating in a region adjacent the prostatic urethra. Themethod of ablative treatment is configured to target smooth muscletissue, alpha adrenergic receptors, sympathetic nerve structures andvasculature parallel to the prostatic urethra between the bladder neckregion and the verumontanum region to a depth of less than 2 cm.

The system can include a vapor delivery mechanism that delivers vapormedia, including water vapor. The system can utilize a vapor sourceconfigured to provide vapor having a temperature of at least 60-140° C.In another embodiment, the system further comprises a computercontroller configured to deliver vapor for an interval ranging from 1second to 30 seconds.

In some embodiments, the system further comprises a source of apharmacologic agent or other chemical agent or compound for deliverywith the vapor. These agents include, without limitation, an anesthetic,an antibiotic or a toxin such as Botox®, or a chemical agent that cantreat cancerous tissue cells. The agent also can be a sealant, anadhesive, a glue, a superglue or the like.

FIG. 1 shows one embodiment of a vapor delivery system. Vapor deliverysystem 100 can have an elongate shaft 102 configured for insertion intothe urethra of a patient and a handle portion 104 for gripping with ahuman hand. The vapor delivery system 100 can include a vapor deliveryneedle 106 disposed in the shaft that is configured to extend from adistal portion of the elongate shaft 102. The vapor delivery needle canextend generally perpendicular to or transverse from the shaft, and caninclude one or more vapor delivery ports configured to deliver a flow ofvapor media from the needle into prostate tissue. The vapor deliverysystem 100 can further include one or more triggers, buttons, levers, oractuation mechanisms 107 configured to actuate the various functions ofthe system. For example, the actuation mechanism can be configured toextend/retract the vapor delivery needle, and start/stop the flow ofvapor, aspiration, and a cooling and/or irrigation fluid such as saline.

In some embodiments, the triggers or actuation mechanisms 107 can bemanipulated in such a way as to control varying degrees or flow rates ofvapor and/or irrigation. In one specific embodiment, the triggers oractuation mechanisms 107 can comprise a first trigger configured toextend/retract the vapor delivery needle, a second trigger configured tostart/stop the flow of vapor, and a third trigger configured to providea cooling and/or irrigation fluid such as saline. In another embodiment,a single trigger or actuation mechanism can both extend/retract thevapor delivery needle and start/stop the flow of vapor. In oneembodiment, a single press or depression of one of the triggers, such asa trigger that provides the cooling and/or irrigation fluid, may providea standard irrigation flush, while a rapid double press or depression ofthe trigger may provide a “turbo” irrigation flush in which the flowrate of irrigation is increased over the standard flush flow rate. Thisfeature may be useful, for example, if the physician encounters ablockage, needs additional cooling, or has reduced vision in the urethraand/or prostate due to accumulation of blood or other bodily fluids.

The fluid or irrigation source can provide a fluid, such as saline,through a separate lumen in the shaft to provide irrigation and flushingto tissue during insertion of the system and during vapor delivery totissue. In some embodiments, the irrigation can be used to clear bloodand debris from tissue lumens to increase visibility. The irrigation canalso provide cooling to the urethra of the patient, both via directcontact of the irrigation fluid with the urethra as well as cooling theshaft of the vapor delivery system as the fluid flows from theirrigation source through the shaft and into contact with the tissue.Urethral flush can be used during the lesion formation. In oneembodiment, the flush rate can be approximately 80 mL / minute, orranging from 20 to 400 mL / minute. Changes in flush rate will changethe amount of tissue cooling (depth) into the urethra and prostate,which can affect lesion size.

FIG. 2A shows a close-up view of the distal portion of the shaft ofvapor delivery system 100, including the vapor delivery needle 106extending beyond the shaft and exposing the vapor delivery ports 108.Vapor delivery ports 108 may be arranged in a pattern that optimizes thedelivery of vapor to tissue in a given application. For example, in asystem designed for treatment of BPH the delivery ports 108 comprisemultiple rows of a plurality of vapor delivery ports. In one specificembodiment, the delivery ports 108 can be spaced at 120 degree intervalsaround the circumference of the needle, with one row of delivery portsfacing distally from the front edge of the needle, as shown in FIG. 2B,to ensure ablation of tissue adjacent to the prostatic urethra. Ingeneral, the vapor delivery ports can each have a unique diameter. Inone embodiment the vapor delivery ports all have the same diameter.

FIG. 2C shows a normal, healthy prostate, and FIG. 2D shows an enlargedprostate being treated with a vapor delivery system 100. In oneembodiment, the vapor delivery system can be inserted into the urethraand advanced to the prostatic urethra through a transurethral approach.The vapor delivery needle 106 can be advanced generally transverse tothe shaft of the vapor delivery system and into the prostate tissue.Vapor can be generated by the vapor delivery system and delivered intothe prostate through the vapor delivery needle. As described above, thevapor delivery needle can include a row of vapor delivery ports thatpoint distally away from the device when the vapor delivery needle isextended transverse to the shaft of the device. Referring to FIG. 2D,the vapor can be delivered to the prostate through this distally facingvapor delivery ports to ablate prostate tissue distal to the position ofthe vapor delivery needle in the prostate. The position of the vapordelivery needle and the vapor delivery ports can allow for ablation oftransition zone tissue of the prostate extending distally from theposition of the vapor delivery needle. For example, in FIG. 2Dtransition zone tissue is treated that extends under bladder musculartissue that cannot be safely penetrated by a delivery device needle.

The vapor delivery system 100 can include a vapor source, an aspirationsource, a fluid cooling or irrigation source, a light source, and/or anelectronic controller configured to control generation and delivery ofvapor from the vapor source, through a lumen of the shaft, through thevapor delivery needle, and into prostate tissue. In some embodiments,the electronic controller can be disposed on or in the vapor deliverysystem, and in other embodiments the electronic controller can bedisposed separate from the system.

A vapor source can be provided for generating and delivering a vapormedia through the vapor delivery needle to ablate tissue. In oneembodiment, the vapor source can be a vapor generator that can deliver avapor media, such as water vapor, that has a precisely controlledquality to provide a precise amount of thermal energy delivery, forexample measured in calories per second. In some embodiments, the vaporsource can comprise an inductive heating system disposed in the vapordelivery system (e.g., in the handle) in which a flow media isinductively heated to generate a condensable vapor such as steam.

FIGS. 3A-3B illustrate one embodiment of an inductive heating system320, comprising an inner fluid coil 322 (shown in FIG. 3A) surrounded byan outer electrically conductive coil 324 (FIG. 3B). The inner fluidcoil can be constructed from steel tubing which may be annealed. Theinner fluid coil may be soldered or include a solder stripe to insureelectrical conductivity between coil windings. The outer conductive coilcan be a conductive material, such as electrically insulated copper Litzwire having an overall diameter ranging from 18 gauge to 22 gauge. Asshown, the inductive heating system 320 can be disposed within the vapordelivery system, such as within the handle. An inlet portion 326 of theinner fluid coil 322 can receive a fluid, such as sterile water, from anexternal fluid source. The fluid can pass through the inner fluid coil322 as AC or RF current is applied to the outer conductive coil 324 viaelectrical connections 325. Current flowing in the outer conductive coilcan induce currents to flow in the inner fluid coil that resistivelyheat the fluid within the inner fluid coil so as to produce a highquality condensable vapor, which is then delivered to the vapor deliveryneedle via outlet portion 328.

FIG. 4 illustrates a generator unit 40 configured to provide power andfluid to the inductive heating system for the production of vapor. Thegenerator unit also can connect to the vapor delivery system 100described above to provide power and other components to the systemvital for operation, such as irrigation/cooling fluid, suction, etc. Thegenerator unit can include an electronic controller and a graphical userinterface (GUI) 434 to provide operating parameters and controls to theuser during vapor therapy. The generator unit can include a syringecradle 430 adapted to hold syringe assembly 536 for providing fluid,such as sterile water, to the inductive heating system.

The generator unit can also include an electrical connector 432 whichcan provide rf current to the inductive heating system, electricalsignals to and from the switches 107 of the vapor delivery system,measurements of, for example, the temperature of the inductive heatingsystem, and electrical signals to/from a controller of vapor deliverysystem, for example in its electrical connector, to identify the vapordelivery system, track its history of vapor delivery, and preventexcessive use of a given vapor delivery system. Generator unit 40 mayalso contain the peristaltic pump 435 that provides a flow ofcooling/irrigation fluid such as saline to the vapor delivery system. Inoperation, flexible tubing 437 can be routed from a bag of sterilesaline, through the peristaltic pump, and through tubing into the vapordelivery system. Guides or markers can be provided on the peristalticpump 435 to insure that the tubing is inserted in a path that providesflow in a direction from the saline bag into the vapor delivery systemwhen the pump is activated normally.

FIG. 5 shows syringe assembly 536 that provides a precise amount offluid such as sterile water to the vapor delivery system 100 forconversion into vapor. Syringe assembly 536 includes a syringe 537having exit port 541 that is offset from the center line of the syringe,with luer fitting 542 that connects to sterile water tubing on the vapordelivery system, plunger 538 that moves forward in the syringe to ejectwater, and backward in the syringe to fill the syringe with water, andaccessory rod 540 that removably attaches to plunger 538 during systemset-up to fill syringe 537. When syringe 537 has been filled with fluid,accessary rod 540 is discarded, and filled syringe 537 is inserted intothe cradle of the generator unit.

FIG. 6 shows a cross-sectional view of the syringe cradle 430 of FIG. 4, with the syringe assembly 536 of FIG. 5 inserted into cradle 430. Acontact switch 654 is activated when syringe 537 is inserted into cradle430 to insure that the syringe is in place when power is delivered tothe vapor delivery system. The state of the contact switch is sensedthrough electrical leads 652. A force sensor 644 is disposed in thecradle such that it contacts and interacts with the cradle and/orsyringe assembly 537. When the electronic controller is commanded todeliver sterile water to the vapor delivery system, piston 642 of thecradle engages syringe plunger 538, and a linear motor attached topiston 642 delivers sterile water at a precisely controlled rate fromsyringe 537 out through luer fitting 542 into fluid tubing connected tothe inductive heating system. As sterile water is pushed, syringe 537impinges on cradle 430, which is free to move laterally within generator40. Forward movement of cradle 430 is prevented as it impinges uponforce sensor 644. Microscopic lateral movement of force sensor 644 istranslated into an electrical signal that is proportional to the forceexerted on force sensor 644 by cradle 430. The electrical signal isconducted through leads 648 to the electronic controller and calibratedas the water pressure within syringe 537 and throughout the fluid tubingincluding within the inner coil of the inductive heating system. Waterpressure is monitored by the electronic controller of the generator unit40, and the electronic controller can be configured to stop delivery ofRF power and fluid to the inductive heating system if the fluid pressurefalls outside of a desired range of pressures, e.g., if the fluidpressure is too low (for example due to a leak in the water line), ortoo high (for example due to a blockage in the water line).

Cradle 430 is configured to purge any air from the fluid tubing during apriming procedure in which water is forced from the syringe and fillsand flushes the system water and vapor lines, exiting from the vapordelivery ports of the vapor delivery device. As shown in FIG. 6 , cradle430 is designed so as to keep the distal end of syringe 537 at a higherelevation than its proximal end when inserted into the cradle, and tokeep offset exit port 541 of the syringe at the top of the syringe. Thisdesign forces any air in the syringe to move under the influence ofgravity to the upper distal end of the syringe and to exit the syringeto be purged from the fluid tubing during the priming procedure. Removalof air from the fluid tubing prevents over heating of the inductiveheating system, and prevents loss of water volume and therefore loss ofcalories delivered to tissue.

The electronic controller of the generator unit can be set to controlthe various parameters of vapor delivery, for example, the controllercan be set to deliver vapor media for a selected treatment interval at aselected flow rate, a selected pressure, or selected vapor quality.Further details on the vapor delivery system, the vapor generator, andhow vapor and fluid are delivered to tissue can be found in U.S. Pat.No. 8,273,079 and PCT Publication No. WO 2013/040209, both of which areincorporated by reference. In some embodiments, the electroniccontroller can also control the aspiration and/or cooling irrigationfunctions of the vapor delivery system.

FIG. 7 provides a cross sectional view of elongate shaft 102 of vapordelivery system 100 from FIGS. 1-2 . Lumen 148 can be configured toaccommodate the vapor delivery needle described above and in FIGS. 1-2 ,to allow for the vapor delivery needle to be advanced from the shaftduring vapor delivery. Lumen 115 formed within tube 112 can have adiameter ranging from about 2 to 5 mm for accommodating variousendoscopes 118, while at the same time providing an annular space 138for allowing an irrigation fluid to flow within lumen 115 and outwardlyfrom the shaft into the distal urethra and bladder. The lumen 115 can besized to accommodate an endoscope or camera to provide additionalviewing and feedback to the physician. This endoscope or camera canprovide a view of the distal end of the shaft, including a view of thevapor delivery needle when deployed. As can be seen in FIG. 7 , thelumen 115 is dimensioned to provide a space 138 for fluid irrigationflow around the endoscope 118. In some embodiments, the annular space138 can be a separate concentric lumen around the endoscope forirrigation fluid flow. The annular space 138 allows for flow ofirrigation fluid from the vapor delivery system into tissue, and alsoprovides cooling to the shaft when vapor is delivered from the vapordelivery needle (disposed in lumen 148) into tissue. Material 144 inFIG. 7 can conduct heat from the vapor delivery needle to theirrigation/cooling fluid flowing in annular space 138, or alternatively,can conduct cooling from the irrigation/cooling fluid to the vapordelivery needle, to prevent over-heating of the patient (particularlythe urethra) during vapor therapy.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

1-8. (canceled)
 9. A vapor delivery system, comprising: a generatorunit; a cradle disposed in the generator unit; a syringe disposed in thecradle; a force sensor disposed in the generator unit and configured tocontact the cradle and/or the syringe, wherein the force sensor isconfigured to generate an electrical signal indicative of a forceexerted on the force sensor by the cradle and/or the syringe; and anelectronic controller configured to receive the electrical signal,wherein the electronic controller is configured to calibrate theelectrical signal to represent a pressure of fluid within the syringe.10. The vapor delivery system of claim 9, wherein the force sensor isdisposed to directly contact the cradle and/or the syringe.
 11. Thevapor delivery system of claim 9, wherein the electronic controller isfurther configured to stop delivery of the fluid if the pressure isoutside of a predetermined range of fluid pressures.
 12. The vapordelivery system of claim 9, wherein the cradle is arranged such that adistal end of the syringe is held at a higher elevation than a proximalend of the syringe.
 13. The vapor delivery system of claim 9, whereinthe cradle further comprises a piston coupled to a linear motor, andwherein the piston interacts with a plunger of the syringe to deliverfluid from the syringe.
 14. The vapor delivery system of claim 9,wherein a contact switch is activated when the syringe is inserted intothe cradle.
 15. A vapor delivery system, comprising: a generator unit; acradle disposed in the generator unit; a syringe disposed in the cradle;a force sensor disposed between the cradle and the generator unit orbetween the syringe and the cradle, wherein the force sensor isconfigured to generate an electrical signal indicative of a forceexerted on the force sensor by the cradle; and an electronic controllerconfigured to receive the electrical signal, wherein the electroniccontroller is configured to calibrate the electrical signal to representa pressure of fluid within the syringe.
 16. The vapor delivery system ofclaim 15, wherein the electronic controller is further configured tostop delivery of the fluid if the pressure is outside of a predeterminedrange of fluid pressures.
 17. The vapor delivery system of claim 15,wherein at least a portion of the cradle is free to move in a lateraldirection perpendicular to a longitudinal axis of the syringe, andwherein the force exerted is a lateral force.
 18. The vapor deliverysystem of claim 15, wherein the cradle further comprises a pistoncoupled to a linear motor, wherein the piston is configured to interactwith a plunger of the syringe to deliver fluid from the syringe.
 19. Thevapor delivery system of claim 18, wherein the interaction of theplunger and the syringe causes the force to be exerted on the forcesensor by the cradle.
 20. The vapor delivery system of claim 15, whereinthe cradle is arranged such that a distal end of the syringe is locatedat a higher elevation than a proximal end of the syringe.
 21. The vapordelivery system of claim 15, wherein a barrel of the syringe directlycontacts the cradle.
 22. A vapor delivery system, comprising: agenerator unit; a cradle disposed in the generator unit; a syringedisposed in the cradle; a force sensor disposed in the generator unitand configured to generate an electrical signal indicative of a lateralforce exerted on the force sensor by the cradle and/or the syringe in alateral direction, wherein the lateral direction is a directionperpendicular to a longitudinal axis of the syringe; and an electroniccontroller configured to receive the electrical signal, wherein theelectronic controller is further configured to calibrate the electricalsignal to represent a pressure of fluid within the syringe.
 23. Thevapor delivery system of claim 22, wherein the electronic controller isfurther configured to stop delivery of the fluid if the pressure fallsoutside of a predetermined range of fluid pressures.
 24. The vapordelivery system of claim 22, wherein at least a portion of the cradle isfree to move laterally within the generator unit.
 25. The vapor deliverysystem of claim 22, wherein the cradle further comprises a pistoncoupled to a linear motor, wherein the piston is configured to interactwith a plunger of the syringe to deliver fluid from the syringe.
 26. Thevapor delivery system of claim 25, wherein the interaction of theplunger and the syringe causes the lateral force to be exerted on theforce sensor by the cradle.
 27. The vapor delivery system of claim 22,wherein the cradle is arranged such that a distal end of the syringe islocated at a higher elevation than a proximal end of the syringe. 28.The vapor delivery system of claim 22, wherein a barrel of the syringedirectly contacts the cradle.